Did you know that #tylenol and or #Acetaminophen has a BLACK BOX label? In the United States, a boxed warning (sometimes "black box warning", colloquially) is a type of warning that appears on the package insert for certain prescription drugs, so called because the U.S. Food and Drug Administration specifies that it is formatted with a 'box' or border around the text. Acetaminophen is the leading cause of acute liver failure in the U.S., causing some 1,600 cases a year. Now the FDA is taking two steps. ... Prescription pain drugs will carry the FDA's strongest "black box" warning label. That label will warn of the risk of serious liver injury.